Resonant power converters utilize a resonant circuit on the primary side of the power converter to create an alternating current (AC) signal applied to a primary winding of a transformer. Electrically-controlled switches on the primary side of the resonant power converter are used to create the AC signal and are controlled by a primary-side controller. The AC signal applied to the primary winding is transferred across the transformer to create an AC signal on the secondary winding. In some cases, the AC signal on the secondary winding is then rectified (e.g., full-wave rectification, half-wave rectification) to supply a direct current (DC) voltage to a load.
Related-art primary-side controllers implement overcurrent protection. That is, when a sustained overload or short circuit occurs on the secondary side (e.g., at the load), the primary-side controller shuts down operation of the resonant power converter to protect the components of the resonant power converter. However, sensing an overload or short circuit condition, and shutting down the resonant power converter, takes a finite number cycles of the AC signal. Thus, substantial overcurrent conditions can occur in both the primary and secondary circuits of the resonant power converter between when the overload or short circuit occurs, and when the primary-side controller senses the condition and shuts down the power converter. Resonant power converter designers thus over-design components of power converters to take into account possible overcurrent conditions, which over-design increases cost, size, and weight of the resonant power converters.